KR890002244B1 - Flow control valve - Google Patents

Abstract

The flow control valve for a vehicle steering, having the characteristics that the supplying flow rate to the oil-pressure equipment is decreased according to the increasement of the pump discharging flow rate, comprises a valve slide (3) in a first bore (2), fixed fitting (4) in a second bore and a sleeve (12) sliding on the fitting (4). The fitting has apertures (4B,4C,4D) which are gradually covered by the slide to reduce the supply as pressure increases due to the restriction (15) provided by a narrowing of the chamber and flange of the sleeve.

Description

Flow control valve

1 is a longitudinal sectional view showing one embodiment of the present invention.

2 and 3 are longitudinal cross-sectional views, respectively, showing important portions of another embodiment.

4 is a front view showing the sleeve of the embodiment of FIG.

5 through 12 are longitudinal cross-sectional views showing important portions of different other embodiments.

* Explanation of symbols for main parts of the drawings

1 housing 2 hole

2d: enlarged diameter part 3: sprue valve

4, 24, 54: Union 4c, 4d: Orifice

6: pump 12, 22, 42, 52: sleeve

12b, 22b, 32b: Flange 15: Restricted passage (gap)

16: ring 17: retainer

18: spring 22c: through hole

32d: notch

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control valve, and more particularly, to a flow control valve having a characteristic in which a supply flow rate to a hydraulic device decreases with the dropping characteristic of the flow rate, that is, the increase in the pump discharge flow rate. will be.

The flow control valve having the above characteristics is generally used for a vehicle power steering device and is useful for vehicle safety at high speeds, for reducing power consumption, and as a device of this kind, for example, a pressure fluid discharged from a pump. An orifice is provided in the supply passage for supplying the oil to the hydraulic equipment, and a sprue valve is opened to reflux a part of the pressure fluid for the pressure difference between the front and rear of the orifice, and a restriction passage is provided in the above supply passage. It has been known in the art to be configured to reduce the orifice by means of a control sprue operating in accordance with the pressure difference before and after this restriction passage. (Japanese Patent Publication No. 104186, Japanese Patent Application Laid-Open No. 57, 4469, etc.).

In addition, in the reduction control of the orifice using the pressure difference before and after the restriction passage, since the pressure difference acts as a loss in the internal pressure of the pump, the effect of reducing the power consumption due to the flow rate decreases, and thus the pressure before and after the restriction passage. It has been proposed to install a relief valve so that the car does not rise more than necessary. (5673, 146472, 57, 4470).

However, any of the flow control valves in the above-described configuration requires fabrication precision due to the complicated structure and the large number of parts, and it is also difficult to tune the characteristics.

Accordingly, it is an object of the present invention to provide a flow control valve capable of obtaining drooping characteristics by an extremely simple configuration.

The purpose of this is to securely attach a tubular union to the opening of the hole for accommodating the spun valve, and to form an orifice for opening the valve by the pressure difference. Is fitted to the union to form a restrictive passage on the outer surface of the sleeve to restrict the passage of pressure fluid, and by sliding the sleeve by the pressure difference between the upstream and downstream of the restrictive passage, the orifice is reduced. Is achieved by one.

In addition, another object of the present invention is to provide a flow control valve that can be regulated so that the pressure difference before and after the restriction passage does not rise more than necessary.

Other objects and advantages of the present invention will become apparent from the following description of the accompanying drawings.

Hereinafter, the present invention will be described according to the embodiments shown in the drawings.

FIG. 1 shows a flow control valve according to an embodiment of the present invention. The housing 1 is formed with a spout valve receiving hole 2 having a large diameter on the opening side, and The spun valve 3 is accommodated in the small diameter portion 2a, and the large diameter portion 2b has one end pushed into the hole 10a of the shaft center portion of the connector 10 to fix the cylindrical union ( 4) is inserted, and the union 4 is fixed in the spout valve receiving hole 2 by screwing the connector 10 into the housing 1.

The large diameter portion 2b of the spout valve receiving hole 2 is connected to the pump 6 via the supply passage 5, and the small diameter portion 2a is disposed through the reflux passage 7. ), The spring valve (3) in the small diameter portion (2a) is applied to the large diameter portion (2b) by the spring (9) and hits the front end surface of the union (4) to stop. Communication between (5) and the reflux path 7 is blocked.

The union 4 has a tubular shape in which the end inserted into the connector 10 is opened, and the end of the sprue valve 3 has a closed bottom, and the vicinity of the closed end 4a. The communication hole 4b which improves and communicates the inside and outside of the cylindrical union 4 in the axial direction is different from the communication hole 4b, and the pair of orifices 4c and 4d are different in the axial position. Is formed.

Therefore, the supply path 5 is interposed between the seal 2c in the large diameter portion 2b of the spun valve receiving hole 2, both orifices 4c and 4d, the communication hole 4b, and the like. The inner passage 4e communicates with the inner passage 4e of the union 4, and the inner passage 4e is powered by the opening 4f of the union 4 and the hole 10a of the shaft center of the connector 10. It is connected to the apparatus PS.

In addition, the inner passage 4e is a chamber 11 accommodating the spring 9 via a radial passage 10b formed in the connector 10 and a communication passage formed in the housing 1 (not shown). Communicate in

Therefore, when the flow rate of the pressure oil discharged from the pump 6 exceeds a predetermined value, the pressure difference between the communication holes 4b and the orifices 4c and 4d before and after the sprue valve 3 By acting and overcoming the spring 9, the sprue valve 3 is moved to the left as shown in the drawing to return a portion of the pressure oil supplied from the pump 6 to the tank 8.

At the outer circumference of the union 4, a cylindrical sleeve 12 having a flange 12b is fitted in a sliding operation.

The sleeve 12 is fitted with a retainer ring 13 fitted to an end portion between the small diameter portion 2a and the large diameter portion 2b of the spun valve receiving hole 2, and the sled. A force is applied to the connector 10 by the spring 14 disposed between the end face 12a of the eve and hits the end face 10c of the connector 10 to stop.

A gap 15 is formed between the outer circumferential surface of the flange 12b of the two-cylinder sleeve 12 and the inner circumferential surface of the hole for receiving the spout valve 2, and the gap 15 is an oil pump 6 The confined passage restricts the flow rate of the pressurized oil supplied from the

Therefore, when the amount of oil supplied from the oil pump 6 exceeds a predetermined value, the sleeve 12 resists the spring 14 by the pressure difference before and after the restriction passage 15, and the sprue valve 3 ) Direction (left in the drawing).

The pair of orifices 4c and 4d is opened when the sleeve 12 is stopped by hitting the end surface of the connector 10, and the sleeve 12 is opened when the sleeve 12 is moved. Installed in the closed position.

The portion near the small diameter portion 2a of the large diameter portion 2b of the spout valve receiving hole 2, that is, the peripheral portion of the side end portion 4a of the male valve valve 3 of the union 4 is provided. An enlarged diameter portion 2d is formed.

Referring to the operation of the flow control valve configured as described above, in the low speed rotation range (less flow range) of the pump 6 driven by the vehicle engine, the sprue valve 3 is driven by the force of the spring 9. The supply path 5 and the reflux path 7 are blocked by coming into contact with the union 4, and the sleeve 12 also stops against the end surface 10c of the connector 10 by the spring 14.

Therefore, the total amount of the pressurized oil discharged from the pump 6 is supplied to the power steering device.

Subsequently, when the pump rotation speed gradually rises, the discharge flow rate increases, and the pump flows to the left of the sprue valve 3 due to the pressure difference before and after the communication holes 4b and the orifices 4c and 4d. When it communicates with the supply passage 5 side, the remaining flow rate is refluxed, and the flow rate supplied to the power steering PS is kept substantially constant. In addition, when the pump rotation speed increases, the pressure difference before and after the restriction passage 15 becomes large this time, and this force overcomes the force which the spring 14 exerts, and makes the sleeve 12 move to the left.

As a result, the sleeve 12 starts to narrow the first orifice 4d first, and then gradually narrows the second orifice 4c to gradually reduce the flow rate to be supplied to the power steering device, The pressure difference before and after 4c) (4d) increases and the sprue valve 3 is moved further to the left to increase the reflux amount.

By reducing the amount of oil supplied to the power steering device in this way, the high speed safety of the vehicle can be improved and the power consumption can be reduced during high speed driving.

When the pump speed increases further and the discharge flow rate from the pump 6 indicates an increase further, the sleeve 12 goes to the left again, and the flange 12b extends to the enlarged diameter portion 2d. When reaching the restriction passage 15, that is, the gap 15 is rapidly enlarged, the increase in the pressure difference between the upstream side and the downstream side of the restriction passage 15 is suppressed.

Thus, the effect of reducing the power consumption can be obtained without applying unnecessary load to the pump 6.

In addition, even after the sleeve 12 is moved to the left and overlapped with both orifices 4d and 4c, the communication hole 4b at the front end of the union is opened, and the flow rate required by the power steering device is at least secured. You can do it.

Even if pressure fluctuations occur in the hydraulic device (power steering) while the sleeve 12 is moved to the left side, the pressure difference before and after the restriction passage 15 does not change because no change occurs in the flow rate flowing through the restriction passage 15. Therefore, the sleeve 12 does not move so that the supply flow rate to the hydraulic device (power steering device) does not change.

As described above, according to this embodiment, the restriction passage 15 is formed between the outer circumferential surface of the sleeve 12 inserted into the outer circumference of the union 4 and the inner surface of the hole 2 of the housing 1, By moving the sleeve 12 by the pressure difference before and after the restriction passage, the function as a variable narrowing valve that gradually narrows the orifices 4c and 4d and the pressure difference before and after the restriction passage 15 are necessary. Since the function as a relief valve which suppresses the above increase can be exhibited, it can manufacture with high reliability and low cost, with a simple structure, without requiring many components like the conventional.

In order to achieve the effect of the present invention, a plurality of orifices are not necessarily required, but the stroke of the sleeve 12 can be increased by displacing the orifices 4c and 4d in the axial direction. Since it is difficult to be affected by machining errors such as the spring constant of the spring 14, it is possible to achieve high precision, and to change the sensitive characteristics by joining orifices of different diameters. You can also get

2 to 5 each show a variation in which it holds sleeves of different shapes, and the flange 22b of the sleeve 22 in FIG. 2 extends outward and its outer diameter is The inside diameter of the large diameter part 2b of the spout valve accommodating hole 2 is substantially corresponded.

Therefore, when the sleeve 22 operates, the outer surface of the sleeve 22 slides along the inner side of the large diameter portion 2b of the spout valve receiving hole 2.

A plurality of through holes 22c are formed in the flange 22b, and these through holes 22c constitute a restriction passage for restricting the flow rate of the pressurized oil supplied from the oil pump 6.

The sleeve 32 of FIG. 3 has an outer diameter flange 32b approximately equal to the inner diameter of the large diameter portion 2b of the spun valve receiving hole 2, and also includes a circumference of the flange 32b. Four notches 32d (refer to FIG. 5) are formed at the edges at intervals such as circumferential directions, and these notches 32d constitute a restriction passage.

The sleeve 42 of FIG. 5 has a thick cylindrical shape, and there is a gap 15 between the outer circumferential surface of the cylindrical sleeve 42 and the inner circumferential surface of the spun valve receiving hole 2. The gap 15 constitutes a restriction passage for restricting the flow rate of the pressurized oil supplied from the oil pump 6.

Also in these Examples 2 and 5, it is apparent that the same effects as those in the above-described Embodiment 1 can be obtained.

The position, shape, number, and the like of the through hole 22c or the cutout portion 32d can be set arbitrarily without being limited to the above.

The means for ensuring the flow rate required by the power steering device at least when the orifice is closed by the sleeve is not limited to the radial communication hole 4b formed in the union 4 as described above. As shown in the figure, an axial passage 34i and a radial groove 34j may be formed in the front end face of the union 34, and as shown in FIG. 7, a part of the inner surface of the sleeve 52 is shown. The outer diameter of the portion 44k in which the inner diameter of the union 44 is formed, or vice versa, is formed as shown in FIG. By making the diameter 12 smaller than the outer diameter of the sliding part, even when the sleeves 52, 12 overlap the orifices 4c, 4d, 44c, 44d, the slides 52 It is good to let (12) leave some clearances between union (4) (44).

In each of the above embodiments, the unions 4, 34, 44 are fixedly attached to the housing 1 via the connector 10. However, it is a matter of course that these unions and the connectors are integrally formed.

However, by making the union into a tubular shape separate from the connector, the workability of the union can be improved, and the union unit is heat-treated to improve the wear resistance of the sliding operation portion with the sleeve. Various effects can be obtained, such as tuning of various characteristics.

In addition, although the spun valve 3 and the union 4, 34, 44 are arrange | positioned on the same axis, it is also possible to arrange these in a right angle or to arrange them in parallel.

The configuration of the orifice is not limited to that of each of the embodiments described above. For example, three or more configurations may be provided, and the shape is not limited to a circular shape and may be various shapes, and the sizes of the plurality of orifices may be different. It is possible to select various positions such as axial and circumferential directions.

In this way, the desired characteristics can be obtained by appropriately setting the number, shape, and the like of the orifices.

9 shows another embodiment, in which a stopper mechanism is provided for restricting the movement of the sleeve 12 more than necessary.

In this embodiment, since it has the same structure as the above-mentioned embodiment of FIG. 1 except for the shape of the union 24, the description is abbreviate | omitted.

The union 24 is formed with a large diameter cylinder portion 24b having an enlarged outer diameter at a portion having the communication hole 24b at its front end.

Therefore, after the sleeve 12 moves and closes the orifices 24d and 24c in turn, the sleeve end surface 12a hits the end 24h of the large diameter cylinder portion 24g and stops. Regulated.

In the figure, 24e is an inner passage, and 24f is an opening.

By providing such a stopper mechanism, the pressure difference before and after the restriction passage 15 becomes excessively large, such as when the temperature is low or the viscosity of the oil is high, so that the sleeve 12 may not be displaced more than necessary. The problem of the strength on the spring 14 can be solved.

Instead of forming the large diameter cylinder portion 24g described above, as shown in FIG. 10, a stopper ring 16 is inserted between the communication hole 4b and the orifice 4c near the communication hole. The sleeve 12 may be brought into contact with the ring.

The eleventh or another embodiment of the present invention is shown, in which the union 54 is a small diaphragm portion which abuts against the large diaphragm portion 54a inserted into the connector 10 and the sprue valve 3. 54b, a radial passage 54d in the small diameter cylinder portion 54b, and an axial position in the portion near the small diameter cylinder portion 54b of the large diameter cylinder portion 54a. Alternatively, two orifices 54c and 54f are formed. On the other hand, the sleeve 54 has an annular bent portion 52b formed on the outer circumference of the flange 52a, and is fitted into the annular bent portion 52b and the small diameter portion 54b of the union 54. A force is applied to the connector 10 by the cylindrical spring 18 disposed between the nugs 17 so as to contact the end surface 10c of the connector 10 and stop.

An annular groove 52c is provided on the inner circumferential surface of the portion where the flange 52a of the sleeve 52 is formed, and the outer circumferential surface of the union 54 and the inner surface of the sleeve 52 do not come into contact with this portion.

Both orifices 54e and 54f are formed so as to be located inside the annular groove 52c when the sleeve 52 is stopped by hitting the connector 10.

According to this embodiment, the drooping characteristics can be obtained in an extremely simple structure similar to each of the above embodiments, and are assembled as a semi-assembled body in which the union 54, the sleeve 52, and the conical spring 18 are integrated. As a result, there is no assembly error or the like and a highly reliable flow control valve can be obtained.

In addition, since the spring 18 is coupled to the front end of the union 54, the pressure oil passing between the windings of the spring 18 is only an adjustment flow rate sent to the power steering device, so that the sleeve 52 is moved in particular. Since the pressure loss at the time of bending the spring 18 is small, there is little influence on the characteristic. Therefore, the whole length can be reduced by shortening the length of the spring 18 in the axial direction.

12 shows another embodiment, in which a stopper mechanism having a different structure is provided.

In this embodiment, the sleeve 62 has substantially the same sleeve 62 as the embodiment of FIG. 11, and the annular bent portion 62b formed at the front end of the flange 62a of the sleeve 62 has a spun valve receiving hole. It extends in the inclined surface 2c direction between the large diameter part 2b of (2), and the small diameter part 2a.

The annular bending portion 62b has a length such that the sleeve 62 slides to close both orifices 54e and 54f in turn, and then comes into contact with the inclined surface 2e to stop the sleeve 62. Holds.

In addition, the annular bent portion 62b is provided with cutouts 62e at the upper and lower portions, respectively, as shown in the drawing, so that the passage of the hydraulic oil can be secured even when the sleeve 62 is in contact with the inclined surface 2e. .

In addition, the annular bent portion 62b is not limited to the one in which a cutout portion is provided, and if a protrusion is formed in a portion to form a passage as the other portion, or a hole is formed, it can be said to be good. There is no thing.

The surface to which the annular bent portion 62b abuts is not limited to one having an inclination, and may be a surface perpendicular to the axis.

In this embodiment, the same effects as in the above embodiments can be obtained, and the anxiety in strength can be solved by the stopper mechanism.

In addition, various shapes, such as a union and a sleeve in each said embodiment, can be combined and applied, unless it contradicts, for example, FIG. 9 to the sleeve of the shape shown in FIGS. And a stopper structure of FIG. 10 or a means for securing a flow rate finally sent to the power steering apparatus as shown in FIGS. 6 to 8 may be applied.

Claims (13)

An orifice (4c) (4d) is provided in the supply passage for supplying the pressure fluid discharged from the pump (6) to the hydraulic equipment, and the sprue valve (3) is opened by the pressure difference before and after the orifice, thereby part of the pressure fluid. In the flow control valve for refluxing, a cylindrical union (4) is inserted into the hole (2) formed in the housing (1) and fixedly attached to the housing. By fitting the eve 12 into the union, a restrictive passage 15 is formed on the outer side of the sleeve to restrict the passage of the pressure fluid, and the sleeve is slid by the pressure difference between the upstream and downstream of the restrictive passage. The flow rate control valve, characterized in that for reducing the orifice. The flow control valve according to claim 1, wherein the sleeve (12) has a flange (12b). 2. A flow control valve according to claim 1, wherein a restriction passage (15) is formed between the flange (12b) outer circumferential surface and the inner surface of the hole (2) formed in the housing (1). The flow control valve according to claim 2, wherein the outer peripheral surface of the flange (12b) is in sliding contact with the inner surface of the hole (2) formed in the housing (1). 5. The flow control valve according to claim 4, wherein the restriction passage is a through hole (22c) formed in the flange (22b). 5. The flow control valve according to claim 4, wherein the restriction passage is a cutout portion (32d) formed at an outer peripheral edge of the flange (32b). 2. The sleeve 42 according to claim 1, wherein the sleeve 42 has a thick cylindrical shape, and the gap 15 between the outer circumferential surface of the sleeve and the inner surface of the hole 2 formed in the housing 1 defines a restriction passage. Flow control valve characterized in that the configuration. The flow control valve according to claim 1, wherein a plurality of orifices (4c) (4d) are formed. 9. The flow control valve according to claim 8, wherein the plurality of orifices (4c) (4d) are provided by displacing positions in the lateral direction of the union (4). 9. The flow control valve according to claim 8, wherein a stopper means for restricting the sliding end of the sleeve (12) is provided. 11. The flow control valve according to claim 10, wherein the stopper means is a protrusion provided on an outer surface of the union (24). 11. A flow control valve as claimed in claim 10, wherein the stopper means is a ring (16) fitted to an outer surface of the union (24). The non-operating position according to claim 1, wherein the sleeve is disposed by a spring 18 disposed between the retainer 17 provided at one end of the union 54 and the end of the sleeve 52. Flow control valve, characterized in that to apply a force.

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